Forming unit for a profiling machine line

ABSTRACT

A forming unit for a profiling machine line, comprising: a plurality of lower rollers ( 11,12,13 ) shaped with outer surfaces that envelop, on at least a transversal section plane, a lower curve (P 1 ); a plurality of upper rollers ( 21,22,23,24,25 ) profiled with outer surfaces that envelop, on the transversal section plane, an upper curve (P 2 ) substantially parallel to the lower curve (P 1 ).

The present invention relates to a forming unit and a profiling machine line for realising profiled elements.

A profiling machine line substantially enables production of longitudinally welded tubes, which are obtained by progressively bending a steel strip about a longitudinal axis, up to bringing the longitudinal edges of the strip into reciprocal contact. The longitudinal edges are welded together to obtain a tube. The tube is cut into sections of a pre-established length, according to known processes. The whole production is performed in a continuous line.

A profiling machine line substantially comprises a series of forming units, arranged in succession, each of which comprises at least two profiling rollers. These forming units are predisposed for progressively bending the steel strip about a longitudinal axis thereof until they confer thereon a tubular conformation. The bending of the sheet is done by passing the strip itself between the rollers of the various forming units which, by contact, progressively deform it. The strip slides continuously through the forming units, being progressively deformed.

A profiling machine line generally comprises at least an initial forming section along which the strip from which the tubes will be obtained is progressively deformed from a flat conformation to one having a U-shaped bend. This deformation is obtained by pairs of rollers, associated to each forming unit, formed by a roller having a concave outer surface and a roller having a convex outer surface. The radii of curvature of the two rollers are substantially equal. The rollers typically have a horizontal rotation axis.

The radii of curvature of the rollers progressively diminish from the start to the end of the forming section, so as to progressively reduce also the radius of curvature of the strip. The rollers of the final zone of the forming section thus have a significant difference between the diameter of the central part thereof and the diameter of the ends thereof. In particular the ends of the concave rollers and the central portion of the convex rollers have rather large diameters, and overall take on a large and unwieldy conformation, as well as being expensive.

The object of the present invention is to provide a forming unit for a profiling machine line which allows the drawbacks summarized above to be obviated.

An advantage of the forming unit according to the present invention is that it enables a considerable reduction in the diameter of the rollers, thus further enabling a reduction in weight and dimensions thereof.

A further advantage of the forming unit according to the present invention is that it can be integrated in already-existing lines.

A further aim of the present invention is to provide a profiling machine line that is particularly advantageous with respect to currently-available lines.

Further characteristics and advantages of the present invention will become more apparent in the following detailed description of an embodiment of the present invention, illustrated by way of non-limiting example in the attached figures, in which:

FIG. 1 is a schematic view of a profiling machine line according to the present invention;

FIG. 1a schematically illustrates the bending of a profiled element (P) starting from the flat configuration of the initial strip;

FIG. 2 illustrates a front view of a forming unit (10) according to the present invention;

FIG. 3 shows the forming group of FIG. 2 in a different operating configuration;

FIG. 4 shows a front view of a guide means (5) according to the present invention.

The profiling machine line, illustrated generally in FIG. 1, guides the starting strip in advancement along a generally horizontal advancement direction (Y). As a skilled person in the sector knows, the starting strip is progressively bent in an upwards curve about a longitudinal axis thereof, assuming a tubular conformation in which the two longitudinal edges (E1, E2) are placed alongside one another and welded. In the following description the starting strip is for convenience indicated as a “profiled element” starting from when deformation thereof begins, by curving upwards about its own longitudinal axis. In the final profiled element (P), the longitudinal edges (E1, E2) of the starting strip are, being welded together, in the upper part of the profiled element (P).

The progressive curving of the strip about its own longitudinal axis preferably occurs in an upwards direction, i.e. by lifting the longitudinal edges (E1,E2) and placing them alongside one another in the upper part of the profiled element (P), as schematically illustrated in FIG. 1a . This allows simplification of the welding operations and subsequent removal of the weld bead, which can take place, still on the processing line, substantially above the profiled element (P) itself. This does not exclude the possibility that the progressive curving of the strip about its own longitudinal axis can take place in a downwards direction, i.e. by lowering the longitudinal edges (E1, E2) and placing them alongside one another in the lower part of the profiled element (P).

The profiling machine line comprises a plurality of working units (10,2 a,2 b,2 c,3 a,3 b,3 c, . . . ) each of which is provided with two or more rollers profiled and arranged so as to produce, on the profiled element (P), a certain curvature about the longitudinal axis thereof. The operating principle of the various working units and the way in which they produce the overall curvature of the profiled element (P) are widely known to a person skilled in the sector.

The profiling machine line has a forming section (1), comprising a plurality of forming units (10) aligned along a first longitudinal direction (Y1). The forming units (10), by means of two or more profiled rollers, produce the initial deformation of the strip, taking it from the flat conformation to a curved conformation, substantially a U-shape, with the concavity thereof facing upwards.

The forming section (1) is followed by a finishing section (2) which comprises a plurality of finishing units (2 a,2 b,2 c, . . . ) aligned along a second longitudinal direction (Y2), substantially coplanar to the longitudinal direction (Y1). The finishing units, by means of a plurality of profiled rollers, continue with the deformation of the strip, processing it into a substantially tubular conformation with the lateral edges parallel and close to one another.

The finishing section is in turn followed by a guide section (3) that comprises a plurality of guide units (3 a,3 b,3 c, . . . ), aligned to one another. The guide units guide the strip, now closed in a tubular configuration, to welding means (4), predisposed to perform a welding of the longitudinal edges of the strip. The guide units (3 a,3 b,3 c, . . . ) comprise a plurality of profiled rollers.

Generally, the starting strip advances along the advancement direction (Y) changing its conformation from substantially flat to tubular, due to the effect of the action exerted along the various sections (1, 2, 3) by the working units (10,2 a,2 b,2 c,3 a,3 b,3 c . . . ).

At least a forming unit (10), illustrated in FIGS. 2 and 3, comprises a plurality of profiled lower rollers (11,12,13) having outer surfaces which envelop, on at least a transversal section plane (S), a lower curve (P1). In particular, the outer surfaces of the lower rollers (11,12,13) envelop a continuous lower curve (P1), i.e. they envelop a lower curve (P1) without any interruptions.

As illustrated in FIG. 2, the transversal section plane is the plane on which the rotation axes of the lower rollers (11,12,13) lie. The lower curve (P1) preferably has concavities facing upwards. As is immediately comprehensible, the predisposing of a plurality of lower rollers (11,12,13) enables obtaining the lower curve (P1), by reducing the maximum diameter required for obtaining the desired curve. In fact, in the forming units at present available which use a single lower roller, the lower curve (P1) can be obtained only by configuring a roller provided with a maximum diameter in the end zone that is decidedly larger. In the forming unit according to the present invention, the lower rollers (11,12,13) can be realised with more modest dimensions.

In a possible embodiment, the lower rollers (11,12,13) comprise a central roller (11) that exhibits a concave outer surface. In other terms, excluding the rotation pins which do not enter into contact with the strip to be deformed, the central roller (11) has a minimum external diameter at a central zone and a maximum external diameter in the end zones. The central roller (11) can be motorised.

The lower rollers can comprise one or more lateral rollers (12,13) each of which is provided with a concave outer surface. In the illustrated embodiment, the concave outer surface of the lateral rollers (12,13), on the transversal section plane, is connected to the outer surface of the central roller (11), so as substantially to define a continuous lower curve (P1).

The lateral rollers (12, 13) have rotation axes that are inclined with respect to the rotation axis of the central roller (11). In the illustrated embodiment the rotation axes of the lateral rollers (12, 13) diverge in a distancing direction from the central roller (11).

At least a forming unit (10) comprises a plurality of upper rollers (21,22,23,24,25) shaped with outer surfaces that envelop, on the transversal section plane, an upper curve (P2). The upper curve (P2) is preferably parallel to the lower curve (P1), i.e. the upper rollers (21,22,23,24,25) are tangential to a curve coinciding with the lower curve (P1). As illustrated in FIG. 2, the transversal section plane is the plane on which the rotation axes of the upper rollers (21,22,23,24,25) lie. The upper curve (P2) preferably has concavities facing upwards. As is immediately comprehensible, the predisposing of a plurality of upper rollers (21,22,23,24,25) enables obtaining the upper curve (P2), reducing the maximum diameter required for obtaining the desired curve. In fact, in the forming units at present available which use a single upper roller, the upper curve (P2) can be obtained only by configuring a roller provided with a maximum diameter in the central zone that is decidedly larger. In the forming unit according to the present invention, the upper rollers (21,22,23,24,25) can be realised with more modest dimensions.

In the illustrated embodiment, the upper rollers comprise a central roller (21) that exhibits a convex outer surface. In other terms, the central roller (21) has a barrel-shaped conformation, with a maximum diameter in a central zone. The upper rollers can further comprise one or more lateral rollers (22,23,24,25) which exhibit a convex outer surface. The outer surfaces of the upper rollers (21,22,23,24,25) are substantially tangential to the upper curve (P2) on the transversal section plane.

In the illustrated embodiment, the forming unit (10) comprises a plurality of lower rollers (11,12,13) and a plurality of upper rollers (21,22,23,24,25). The rotation axes of the rollers lie on a same transversal section plane. The upper curve and the lower curve (P2,P1) both lie on the transversal section plane. The upper curve and the lower curve (P2,P1) are substantially parallel to one another.

The strip to be processed and bent about the longitudinal axis thereof passes in contact with the lower rollers and the upper rollers, substantially assuming a curvature parallel to the upper curve and the lower curve (P2, P1).

Preferably, though not necessarily, the upper rollers (21,22,23,24,25) are associated with an upper support (20), which is movable along a vertical direction. This enables adjusting the distance between the upper rollers and the lower rollers, for example in relation to the thickness of the strip to be processed. This further enables adjusting the pressure that the rollers exert on the strip under process.

The upper support (20) has overall a curved conformation, with a concavity facing upwards. The support (20) is further provided with seatings for rotatably housing the upper rollers (21,22,23,24,25).

The upper support (20) can be associated to a cross-member (26) which is vertically slidable along a support structure (9). Means known to a person skilled in the sector can be predisposed to command the displacement of the upper support (20). In the illustrated version the support structure comprises two uprights (91, 92).

The lower rollers (11, 12, 13) can be associated to the uprights (91, 92).

The central roller (11) is associated to the uprights at the ends thereof, by means of a shaft or by rotation pins. The lateral rollers (12.13) are each associated to a respective upright.

The lower rollers (11, 12, 13) can be associated to a lower support (14). The lower support (14) comprises two portions (14) to each of which is rotatably associated an end of the rotation shaft of the central roller (11). Each support portion (14) further rotatably supports one of the lateral rollers (12, 13). In particular each support portion (14) bears a pair of shelf members (14 a) to which the ends of the rotation shaft of the respective lateral roller are associated.

The two opposite portions of the lower support (14) are each associated to one of the uprights (91, 92), preferably vertically slidably, for enabling the adjustment of the position of the lower rollers (11,12,13). Means known to a person skilled in the sector can be predisposed to command the vertical displacement of the lower support (14).

The profiling machine line can advantageously be provided with at least a working unit (10,2 a,2 b,2 c,3 a,3 b,3 c . . . ) a position of which is vertically adjustable independently with respect to the other working units. By adjusting the vertical position of at least a working unit it is possible to set a predetermined curvature for the profiled element (P). For example, by lowering the position of a working unit with respect to the following working units, a curvature can be set for the profiled element (P) which is concave facing upwards followed by a curvature that is concave facing downwards. In the downwards-facing concavity section the upper zones of the profiled element (P) are stretched, in particular the zones of the longitudinal edges (E1, E2) which assume a stretched conformation that is substantially free of undulations, or having very modest undulations.

In a possible embodiment the profiling machine line is provided with an intermediate section, comprising one or more working units, which is rotatable about a horizontal axis (X) with respect to a first preceding section, in turn comprising one or more working units. Rotation means, not illustrated, can be predisposed to produce this rotation. The line further comprises a third section, comprising one or more working units, which is subsequent with respect to the intermediate section and the position of which on a vertical plane is adjustable. This enables inclining the profiled element (P) upwards, thanks to the possibility of rotating the intermediate section about the horizontal axis (X) and returning the profiled element (P) consecutively to the intermediate section and along the third section, in a substantially horizontal inclination that is in any case smaller than the inclination assumed in the intermediate section of the line. In this way, in passing from the intermediate section to the third section of the line, the profiled element (P) is subjected to a bending operation, a concavity of which is facing upwards. The whole zone of the edges (E1, E2) of the profiled element (P) which are to be welded to one another is therefore stretched to assume a stretched conformation that is substantially free of undulations, or has very modest undulations. This significantly facilitates the welding of the longitudinal edges and the realisation of a weld bead that is structurally solid. The intermediate section might be provided with a base to which one or more working units are fixed. The base might be hinged about the horizontal axis (X) to a preceding working unit.

For example, the finishing section (2) can be rotatable about a horizontal axis (X) relative to the forming section (1). This enables adjusting the inclination of the second longitudinal direction (Y2) relative to the first longitudinal direction (Y1).

As already specified, the finishing section (2) can be inclined upwards (by a few degrees). As it enters the guide section (3) consecutive to the finishing section (2), the profiled element (P), which has by now taken on a tubular configuration, undergoes a bending a concavity of which is facing downwards. The whole zone of the edges (E1, E2) of the profiled element which are to be welded to one another is therefore stretched to assume a stretched conformation that is substantially free of undulations, or has very modest undulations. This significantly facilitates the welding of the longitudinal edges and the realisation of a weld bead that is structurally solid.

In a possible embodiment, at least one of the finishing units (2 a,2 b,2 c, . . . ) is rotatable about a horizontal axis (X) relative to the forming section (1). In the illustrated embodiment, the finishing section (2) comprises a base (B2), to which the finishing units (2 a, 2 b, 2 c, . . . ) are constrained, which base (B2) is hinged, relative to the horizontal axis (X), to an end portion of the forming section (1). For example the base (B2) can be hinged to a base portion of the nearest forming unit (10). Alternatively, the forming section (1) can in turn be provided with a base (B1) to which the forming units (10) are associated. With reference to the advancement direction of the profiled element (P), a front end of the second base (B2) can be hinged to a rear end of the first base (B1). Actuator means known to the expert in the sector can be used for determining the rotation of the finishing section (2) about the horizontal axis (X).

The profiling machine line can advantageously be provided with guide units (3 a, 3 b, 3 c, . . . ) that are vertically mobile independently of one another. In other terms, the vertical position of each guide unit can be adjusted independently with respect to the vertical position of the other guide units. This enables giving the transiting profiled element (P) a predetermined curvature on a vertical longitudinal plane thereof. For example, in the same way as already described with respect to the finishing group (2), it is possible to give the profiled element (P) a curvature the concavity of which is facing downwards. The whole zone of the edges of the profiled element (P) which are to be welded to one another is therefore stretched to assume a stretched conformation that is substantially free of undulations, or has very modest undulations. This significantly facilitates the welding of the longitudinal edges and the realisation of a weld bead that is structurally solid. The guide units (3 a,3 b,3 c, . . . ), vertically mobile independently of one another, can be present, in the presence or absence of the finishing section (2), rotatable about the horizontal axis (X) with respect to the forming section (1). For example, in the presence of an upwards-inclined finishing section (2), the 10 o vertical position of the guide units (3 a,3 b,3 c, . . . ) can be adjusted so as to bend the profiled element (P) downwards to overall define a continuous curvature with the concavity facing downwards. This produces a consistent stretching of the edges of the profiled element (P) which assume a stretched and straight configuration.

The profiling machine line can be provided with guide means (5), interposed for example between the forming section (1) and the finishing section (2), which are so structured as to push the edges (E1, E2) of the profiled element (P) under process one towards the other.

The guide means (5), illustrated schematically in FIG. 4, preferably comprise a pair of shoes (51,52), fixed opposite one another, and positioned so as to enter into contact with two opposite zones of the article (P). For example, the shoes (51, 52) are positioned so as to enter into contact with zones close to the edges (E1, E2) of the profiled element (P) under process.

In a possible embodiment the shoes (51, 52) are associated to a foot or support structure and are located at a predetermined height, preferably adjustable. The shoes (51,52) prevalently extend along a longitudinal direction parallel to the advancement direction (Y). On a section plane that is vertical and perpendicular to the advancement direction (Y), the shoes (51, 52) are preferably inclined so as to converge towards one another. The shoes (51, 52) can be positioned for example in a section of the intermediate line between two working units, passing through which the edges (E1, E2) of the profiled element (P) begin to be inclined, turning towards one another. This facilitates the passage from the preceding working unit to the working unit positioned following the shoes (51, 52). For example the shoes (51, 52) can be positioned between the forming section and the finishing section. The shoes (51, 52) are preferably associated to respective supports (51 a, 52 a) that are horizontally and vertically mobile, as schematically illustrated in FIG. 4. 

1. A forming unit for a profiling line, characterized by comprising: a plurality of lower rollers (11,12,13) shaped with outer surfaces that envelop, on at least one transversal section plane, a lower curve (P1); a plurality of upper rollers (21,22,23,24,25) shaped with outer surfaces that envelop, on the transversal section plane, an upper curve (P2) substantially parallel to the lower curve (P1).
 2. A forming unit according to claim 1, in which the lower rollers (11,12,13) exhibit axes of rotation lying on the transversal section plane.
 3. A forming unit according to claim 1, wherein at least one of the upper rollers (21,22,23,24,25) exhibits its axis of rotation lying on the transversal section plane.
 4. A forming unit according to claim 1, wherein the upper rollers (21,22,23,24,25) are associated with a support (20), which is movable along a vertical direction.
 5. A forming unit according to claim 1, in which the lower rollers (11,12,13) include a central roller (11) that exhibits a concave outer surface.
 6. A forming unit according to claim 5, in which the lower rollers comprise one more lateral rollers (12,13) each of which is provided with a concave outer surface that, on the transversal section plane, is matched to the outer surface of the central roller (11).
 7. A forming unit according to claim 5, in which the central roller (11) is motorized.
 8. A forming unit according to claim 1, wherein the upper rollers comprise a central roller (21) that exhibits a convex outer surface.
 9. A forming unit according to claim 8, comprising one or more lateral rollers (22,23,24,25) which exhibit a convex outer surface.
 10. A profiling machine line for the realization of profiled elements, comprising a plurality of working units (10,2 a, 2 b, 2 c, 3 a, 3 b, 3 c, . . . ) each of which is provided with two or more rollers which are shaped and arranged such as to form on the profiled elements (P) a certain curvature about its longitudinal axis, characterized in that it comprises at least one working unit (10,2 a, 2 b, 2 c, 3 a, 3 b, 3 c . . . ) the position of which is vertically adjustable independently of the other working units.
 11. A profiling machine line for the realization of profiled elements according to claim 10, comprising an intermediate section, which is rotatable about a horizontal axis (X) with respect to a first previous section, and a third section following the intermediate section, the position of which is adjustable on a vertical plane.
 12. A profiling machine line for the realization of sections, comprising: a forming section (1), comprising a plurality of forming units (10) according to claim 1, aligned along a first longitudinal direction (Y1); a finishing section (2), consecutive to the forming section (1), comprising a plurality of finishing units (2 a, 2 b, 2 c, . . . ) aligned along a second longitudinal direction (Y2); a guide section (3), consecutive to the finishing section (2), comprising a plurality of guide units (3 a, 3 b, 3 c, . . . ), mutually aligned, and welding means (4), prepared for performing a parallel welding to the longitudinal direction (Y); characterized in that the finishing section (2) is rotatable about a horizontal axis (X) relative to the forming section (1), so as to adjust the inclination of the second longitudinal direction (Y2) with respect to the first longitudinal direction (Y1).
 13. A profiling machine line according to claim 12, in which the finishing section (2) comprises a base (B), to which the finishing units (2 a, 2 b, 2 c, . . . ) are constrained, which base (B) is hinged, relative to the horizontal axis (X), to an end portion of the forming section (1).
 14. A profiling machine line according to claim 12, in which the guide units (3 a, 3 b, 3 c, . . . ) are vertically movable independently of each other.
 15. A profiling machine line according to claim 12, comprising guide means (5), which is so structured as to push the edges (E1, E2) of the profile (P), one towards the other.
 16. A profiling machine line according to claim 15, wherein the guide means (5) comprises a pair of opposing shoes (51,52), being so positioned as to come into contact with two zones of the article (P). 